256x256 px icons

[Warren Young]

On 8/15/2011 9:44 AM, Charles Wilson wrote:
> On 8/15/2011 10:33 AM, Warren Young wrote:
>> The hard edges in the original art are causing stair-stepping when doing
>> a direct downsample, though.  (Look at the pointy bits.)  By blurring
>> the high-res version and then downsampling by a non-integral amount, you
>> can get a much smoother result.
>
> This is only the case if the "downsample" operation used by GIMP, when
> d/s by an integral amount, is to simply pick every Nth pixel.  That's
> very fast -- but is not the correct operation (I'd posit a GIMP bug, in
> fact).

Perhaps Gimp did that in the past, but what you're describing is now 
Gimp's "None" interpolation mode.  Both it and Photoshop have better 
resampling modes, but they all give some stair-stepping with hard 
diagonal lines if you don't give it a bit of help.